4 Spatial distribution of priority fisheries and fishing effort
One of the most basic issues that is important for fisheries management is the understanding of the the distribution of key indicators and whether they change both in space and time. The common approach that is widely used in fisheries management is taking statistics at the receiving hand—landing sites. The central problem is that doing that only provide reference of the catch at the receiving hand—landing sites and ignore the source of fishery resource—fishing grounds. In this chapter we discuss catch rates, income and fishing effort at the collaborative fisheries managed areas (CFMA) and compare how they vary both in space and time.
The Kibiti, Mafia and Kilwa seascape (Figure 4.1) is a unique coastal areas because of myriad coastal habitats like magroves, seagrass and coral reefs, discharge of Rufiji River that form the largest estuary in the region, the change of speed and direction of trade winds that form monsoon winds, and the bathing of the East African Coastal Current that mix the water continuously.
4.1 e-CAS
4.1.1 Fishery Data Available
The electronic catch assessment survey (e-CAS) system trial data collection begun in 2017 and until the end of 2020, recorded 5504 information of different marine fish species. Most of these information were recorded in the Kilwa district (3613), followed by Mafia (1629) and Kibit district has the lowest number of 262 in the e-CAS platform.
| district | Elasmobranch | Octopus | Others | Prawn | Reef Fish | Small Pelagic | Tuna | Total |
|---|---|---|---|---|---|---|---|---|
| Kibiti | 5 | 0 | 144 | 45 | 16 | 52 | 0 | 262 |
| Kilwa | 146 | 11 | 71 | 0 | 2701 | 624 | 60 | 3613 |
| Mafia | 61 | 355 | 192 | 0 | 720 | 206 | 95 | 1629 |
| Total | 212 | 366 | 407 | 45 | 3437 | 882 | 155 | 5504 |
The records in the e-CAS vary not only by the priority fishery but also for the collaborative fisheries managed areas (CFMAs). For instance, Figure 4.2 illustrated the reef fishery records constitute more than 62 percent and most of these records are from the Nyamanjisopoja CFMA. The small pelagic fishery constitute about 16 percent of the total records and like reef fish, most records are from Nyamanjisopoja CFMA (Figure 4.2). Other priority fishery are distributed across CFMAs at small proportions.
Though octopus and prawns are among important fisheries in the area, but their records in the e-CAS are few. For instance, we found that Octopus fishery is most recorded at BK CFMA and no single value of octopus has been recorded in CFMAS like Nyamanjisopoja (Figure 4.3), which has the highest records of Reef and small pelagic fishery. The absent of octopus fishery in other CFMA suggest that records in the e-CAS is fishery priority specific.
The fisheries governance framework in Kibiti, Mafia and Kilwa seascape is centred around the establishment of collaborative fisheries management areas (CFMAs). CFMAs are jointly managed by neighbouring BMUs who share fishing grounds. Among many key objectives of CFMA include conducting fishing pattern surveys and identifying priority fisheries. A functioning CFMA usually has BMU Statistics Committee capable to collect and analyse fisheries data for internal decision making. They are familiar with types and uses of fisheries data and guided through the process of designing and reviewing a data collection protocol.
Reporting of fisheries data in the electronic catch assessment system often depend on the collaboration with beach management unit (BMU). The willingness of BMU in a particular CFMA is key for successful data entry. We found that data entry into the e-CAS system relate closely to the BMU operations and data vary accordingly. For instance, more than 88 percent of data in Kibiti recorded fished at Mchimchunya CFMA (Figure 4.5). Similar to Kibiti, in Mafia the records in Mafia was dominated with fish from BK CFMA (Figure 4.6) and Nyamanjisopoja recorded a stagerring 85% of records in the e–CAS (@(Figure 4.7))
4.1.2 Catch Rates
4.1.3 Income
4.1.4 Effort (Number of Active Fishers)
